Complete newbie here. I read that all the scope's magnification is in the eyepiece, but you're attaching a camera in place of the eyepiece? Then how do you get astrophotos with magnification?
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Thanks for the replies. I have an Orion 8" f/3.9 Astrograph Reflector coming next month (backorder), which will attach to an Atlas go-to mount. I plan to get a color camera, probably from ZWO. I have to say, Galactic-Hunter helped influence my decision for the scope and mount.
@rjhanby gave a great explanation! Two things I would add:
- If the camera used is high quality and has small pixels, then it is simple to zoom in / crop the final image by quite a lot and still retain a great quality
- Barlows are usually not a good idea when using a camera for deep sky imaging as most barlows tend to introduce some blur or in some cases star distortions on the edges, but can be very good when the target is the moon or a planet.
With an eyepiece you divide the scopes focal length by the eyepiece focal length to get the magnification. 500 mm / 25 mm = 20x. With a camera, you use the diagonal of the sensor. For a full frame 35 mm sensor, the diagonal would be about 42.25 mm so 500 mm / 42.5 mm = about 12x, good for big objects, not so good for galaxies or bright planets. Move up to 1800 mm and you get about 43x, much better. If the target is bright, add a barlow or tele view to double (or better). Those were simplistic examples, I would think the back focus length (think projecting an image on a wall) would also come into play.